import * as THREE from "three";
import GUI from "lil-gui";
import mfragment from "@a/demo/fragment.glsl";
//创建gui
const gui = new GUI();

//创建场景
const scene = new THREE.Scene();
//创建透视相机 还有
const camera = new THREE.PerspectiveCamera(
  //fov：透视相机视线角度，单位为弧度。例如，fov值为60度时，摄像机视野范围为水平方向90度，垂直方向90度。
  45,
  //aspect：摄像机的宽高比。例如，当宽高比为2时，摄像机宽度为高度的两倍。
  window.innerWidth / window.innerHeight,
  //near：摄像机焦距距离，单位为像素。例如，当near值为0.1时，远近平面距离为100像素
  0.1,
  //far：摄像机裁剪距离，单位为像素。例如，当far值为1000时，超过该距离的物体将不会被渲染。
  1000
);

camera.position.set(0, 1, 8);

//创建立方体
const geometry = new THREE.SphereGeometry(1, 256, 256);
//创建立方体材质

/**
 * 在计算机图形学中，噪声（Noise）指的是一类随机生成的值，
 * 输出的每个值都是独立且均匀分布的。
 * 噪声函数可以用于生成各种复杂的、看起来像自然现象的图案，比如云朵、大理石、柏油等等。
 * 噪声函数可以用于模拟各种自然现象，如风、雨、雪、火焰等等。
 */

//(顶点着色器)
const vertex = `
//	Classic Perlin 3D Noise 
//	by Stefan Gustavson
vec4 permute(vec4 x){return mod(((x*34.0)+1.0)*x, 289.0);}
vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;}
vec3 fade(vec3 t) {return t*t*t*(t*(t*6.0-15.0)+10.0);}
//噪声函数
float cnoise(vec3 P){
  vec3 Pi0 = floor(P); // Integer part for indexing
  vec3 Pi1 = Pi0 + vec3(1.0); // Integer part + 1
  Pi0 = mod(Pi0, 289.0);
  Pi1 = mod(Pi1, 289.0);
  vec3 Pf0 = fract(P); // Fractional part for interpolation
  vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
  vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
  vec4 iy = vec4(Pi0.yy, Pi1.yy);
  vec4 iz0 = Pi0.zzzz;
  vec4 iz1 = Pi1.zzzz;

  vec4 ixy = permute(permute(ix) + iy);
  vec4 ixy0 = permute(ixy + iz0);
  vec4 ixy1 = permute(ixy + iz1);

  vec4 gx0 = ixy0 / 7.0;
  vec4 gy0 = fract(floor(gx0) / 7.0) - 0.5;
  gx0 = fract(gx0);
  vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
  vec4 sz0 = step(gz0, vec4(0.0));
  gx0 -= sz0 * (step(0.0, gx0) - 0.5);
  gy0 -= sz0 * (step(0.0, gy0) - 0.5);

  vec4 gx1 = ixy1 / 7.0;
  vec4 gy1 = fract(floor(gx1) / 7.0) - 0.5;
  gx1 = fract(gx1);
  vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
  vec4 sz1 = step(gz1, vec4(0.0));
  gx1 -= sz1 * (step(0.0, gx1) - 0.5);
  gy1 -= sz1 * (step(0.0, gy1) - 0.5);

  vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
  vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
  vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
  vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
  vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
  vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
  vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
  vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);

  vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
  g000 *= norm0.x;
  g010 *= norm0.y;
  g100 *= norm0.z;
  g110 *= norm0.w;
  vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
  g001 *= norm1.x;
  g011 *= norm1.y;
  g101 *= norm1.z;
  g111 *= norm1.w;

  float n000 = dot(g000, Pf0);
  float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
  float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
  float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
  float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
  float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
  float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
  float n111 = dot(g111, Pf1);

  vec3 fade_xyz = fade(Pf0);
  vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
  vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
  float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x); 
  return 2.2 * n_xyz;
}
//随机函数
float random(vec3 pos){
  return fract(sin(dot(pos, vec3(64.25375463, 23.27536534, 86.29678483))) * 59482.7542);
}
//自定义变量
uniform float uTime; 
uniform float uStrength;
uniform float uFrequency;
//声明的变量
varying vec2 vUv;
varying vec3 vNormal;
varying float vNoise;
//每个顶点自带的属性有 position、uv 和 normal(法线)
  void main() {
    vec3 newPos = position;
    float noise = cnoise(position * uFrequency + uTime);
    newPos += normal * noise *1.0;
    vNoise = noise;
    gl_Position = projectionMatrix * modelViewMatrix * vec4(newPos, 1.0);
  }
`;

//(片元着色器)
const fragment = `
varying vec2 vUv;
varying vec3 vNormal;
varying float vNoise;

float hue2rgb(float f1, float f2, float hue) {
  if (hue < 0.0)
      hue += 1.0;
  else if (hue > 1.0)
      hue -= 1.0;
  float res;
  if ((6.0 * hue) < 1.0)
      res = f1 + (f2 - f1) * 6.0 * hue;
  else if ((2.0 * hue) < 1.0)
      res = f2;
  else if ((3.0 * hue) < 2.0)
      res = f1 + (f2 - f1) * ((2.0 / 3.0) - hue) * 6.0;
  else
      res = f1;
  return res;
}

vec3 hsl2rgb(vec3 hsl) {
  vec3 rgb;
  
  if (hsl.y == 0.0) {
      rgb = vec3(hsl.z); // Luminance
  } else {
      float f2;
      
      if (hsl.z < 0.5)
          f2 = hsl.z * (1.0 + hsl.y);
      else
          f2 = hsl.z + hsl.y - hsl.y * hsl.z;
          
      float f1 = 2.0 * hsl.z - f2;
      
      rgb.r = hue2rgb(f1, f2, hsl.x + (1.0/3.0));
      rgb.g = hue2rgb(f1, f2, hsl.x);
      rgb.b = hue2rgb(f1, f2, hsl.x - (1.0/3.0));
  }   
  return rgb;
}

vec3 hsl2rgb(float h, float s, float l) {
  return hsl2rgb(vec3(h, s, l));
}

void main() {
 vec3 color = hsl2rgb(0.1 + vNoise * 0.1,3.0, 0.2);
  gl_FragColor = vec4(color, 1.0);
}
`;

const material = new THREE.ShaderMaterial({
  /**
   * 在 ShaderMaterial 里可以通过 uniforms 从主程序 js 里传入所需的变量，
   * 其在顶点着色器和片元着色器里都能获取到，且对于每个顶点或片元数值统一相同，
   * 注意设置时不是 uTime: 0 这样的格式，后面必须是对象格式 uTime: { value: 0 }，
   * 其他 uniform 变量同理。
   */
  uniforms: {
    uTime: { value: 0 },
    uStrength: { value: 0.5 },
    uFrequency: { value: 5.0 }
  },
  //顶点着色器
  vertexShader: vertex,
  //片元着色器
  // fragmentShader: fragment,
  fragmentShader: mfragment,
  /* 配合抗锯齿 */
  extensions: { derivatives: true },
  /* 线框模式 */
  wireframe: false
});
/**
 * 首先需要在 uniforms 里添加所需的变量 uFrequency 和 uStrength 并设置初始值，
 * 接着通过 gui 对这些变量的 value 值进行控制，并设置不同的范围。
 */
gui.add(material.uniforms.uStrength, "value", 0, 1, 0.01).name("uStrength");

gui.add(material.uniforms.uFrequency, "value", 0, 20, 0.01).name("uFrequency");

//网格
const mesh = new THREE.Mesh(geometry, material);
mesh.position.set(0, 0.8, 0);
scene.add(mesh);

//渲染器
const renderer = new THREE.WebGLRenderer({
  //抗锯齿
  antialias: true
});
//设置像素比，解决retina屏幕模糊问题
renderer.setPixelRatio(Math.min(window.devicePixelRatio, 1));
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor("#e6fcf5", 1);
document.body.appendChild(renderer.domElement);

//添加网格地面
// const GridHelper = new THREE.GridHelper(10, 10);
// scene.add(GridHelper);

//动画
let time = 0;
function animate() {
  time += 0.02;
  material.uniforms.uTime.value = time;
  // 请求下一次动画渲染
  requestAnimationFrame(animate);
  // mesh的旋转属性递增
  mesh.rotation.x += 0.01;
  mesh.rotation.y += 0.01;
  // 使用渲染器渲染场景
  renderer.render(scene, camera);
}
animate();
